Such apparatus can be particularly but not exclusively used in connection with tubular centrifuging techniques where a tube is cut transversely at a point corresponding to the point of contact between phases separated by centrifuging and in order to recover these phases separately.
These phases may be liquid or solid.
At the present time use is made for this purpose of a thin cutting blade, such as a razor blade, which in use is held in one hand and used to cut a tube, which is held in the other hand. As the diameter of the tube is usually small, generally of the order of a few millimetres, the phases contained respectively in the two length of tubing are retained therein by capillary action.
This method has the disadvantages that the cut is not clean, involving a risk of leakage, and, owing to the distortion of the tube by the application of the blade, a risk of the phases which have been separated getting mixed together again, or at least of the passage of one of the phases beyond the point of cutting.